CSS Regions and Events

•To handle a layout and make sure your content displays right, you can make use of JavaScript events in combination with regions.
•Regions specification defines the events that could be used to react to specific conditions.
•The regionoversetchange event dispatches when the property regionOverset changes in any region.
•The regionOverset value is fit, overset or empty.
•empty means there is no content inside your region. overset is set when the final region in your chain cannot display the rest of the content. This will make some of your content unreadable.
• fit value makes the content fit properly inside the region, completely or partially .
• These events can be used to add or remove regions dynamically or to make a class that changes its layout.